Python script for converting MARC 21 Classification and MARC 21 Authority records (serialized as MARCXML) to SKOS concepts.
Initially developed to support the project "Felles terminologi for klassifikasjon med Dewey", for converting Dewey Decimal Classification (DDC) records. Issues and suggestions for generalizations and improvements are welcome!
See mapping schema for MARC21 Classification and for MARC21 Authority below.
Releases can be installed from the command line with pip:
$ pip install --upgrade mc2skos # with virtualenv or as root
$ pip install --upgrade --user mc2skos # install to ~/.local
- Works with both Python 2.7 and 3.4+. See Travis for details on tested Python versions.
- If lxml fails to install on Windows, try the windows installer from from PyPI.
- If lxml fails to install on Unix, install system packages python-dev and libxml2-dev
- Make sure the Python scripts folder has been added to your PATH.
To directly use a version from source code repository:
$ git clone https://github.com/scriptotek/mc2skos.git
$ cd mc2skos
$ pip install -e .
mc2skos infile.xml outfile.ttl # from file to file
mc2skos infile.xml > outfile.ttl # from file to standard output
Run mc2skos --help
or mc2skos -h
for options.
URIs are generated automatically for known concept schemes, identified from
084 $a
for classification records and from 008[11]
/ 040 $f
for
authority records. To list known concept schemes:
$ mc2skos -l
To add more vocabularies, you can edit vocabularies.yml. Pull requests for adding more vocabularies are very welcome!
URIs can be also be generated on the fly from an URI template specified with option
--uri
. The following template parameters are recognized:
{control_number}
is the control number from 001, 010 or 016. The current approach is to use 010 or 016 if defined, otherwise 001. If you find examples where this approach fails, please add them to [#42](#42).{collection}
is "class", "table" or "scheme"{object}
is a member of the classification scheme and part of a{collection}
, such as a specific class or table. Spaces in the URI are replaced by hyphens or another character configured with option --whitespace.{edition}
is taken from084 $c
(with language code stripped)
To add skos:inScheme
statements to all records, an URI template can be
specified with option --scheme
. Otherwise, it will be derived from a default
template if the concept scheme is known.
To add an additional skos:inScheme
statement to table records, an URI
template can be specified with option --table_scheme
. Otherwise, it will be
derived from a default template if the concept scheme is known.
The following example is generated from a DDC table record:
<http://dewey.info/class/6--982/e21/> a skos:Concept ;
skos:inScheme <http://dewey.info/scheme/edition/e21/>,
<http://dewey.info/table/6/e21/> ;
skos:notation "T6--982" ;
skos:prefLabel "Chibchan and Paezan languages"@en .
Only a small part of the MARC21 Classification data model is converted, and the conversion follows a rather pragmatic approach, exemplified by the mapping of the 7XX fields to skos:altLabel.
MARC21XML | RDF |
---|---|
001 Control Number (see note above on 001, 010 & 016) |
dcterms:identifier |
005 Date and time of latest transaction |
dcterms:modified |
008[0:6] Date entered on file |
dcterms:created |
008[8]="d" or "e" Classification validity |
owl:deprecated |
010 Control Number (see note above on 001, 010 & 016) |
dcterms:identifier |
016 Control Number (see note above on 001, 010 & 016) |
dcterms:identifier |
153 $a , $c , $z Classification number |
skos:notation |
153 $j Caption |
skos:prefLabel |
153 $e , $f , $z Classification number hierarchy |
skos:broader |
253 Complex See Reference |
skos:editorialNote |
353 Complex See Also Reference |
skos:editorialNote |
680 Scope Note |
skos:scopeNote |
683 Application Instruction Note |
skos:editorialNote |
684 Auxiliary Instruction Note |
skos:editorialNote |
685 History Note |
skos:historyNote |
700 Index Term-Personal Name |
skos:altLabel |
710 Index Term-Corporate Name |
skos:altLabel |
711 Index Term-Meeting Name |
skos:altLabel |
730 Index Term-Uniform Title |
skos:altLabel |
748 Index Term-Chronological |
skos:altLabel |
750 Index Term-Topical |
skos:altLabel |
751 Index Term-Geographic Name |
skos:altLabel |
753 Index Term-Uncontrolled |
skos:altLabel |
765 Synthesized Number Components |
mads:componentList (see below) |
Components of synthesized numbers explicitly described in 765 fields are expressed using the mads:componentList property, and to preserve the order of the components, we use RDF lists. Example:
@prefix mads: <http://www.loc.gov/mads/rdf/v1#> .
<http://dewey.info/class/001.30973/e23/> a skos:Concept ;
mads:componentList (
<http://dewey.info/class/001.3/e23/>
<http://dewey.info/class/1--09/e23/>
<http://dewey.info/class/2--73/e23/>
) ;
skos:notation "001.30973" .
Retrieving list members in order is surprisingly hard with SPARQL. Retrieving ordered pairs is the best solution I've come up with so far:
PREFIX mads: <http://www.loc.gov/mads/rdf/v1#> PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX skos: <http://www.w3.org/2004/02/skos/core#> SELECT ?c1_notation ?c1_label ?c2_notation ?c2_label WHERE { GRAPH <http://localhost/ddc23no> { <http://dewey.info/class/001.30973/e23/> mads:componentList ?l . ?l rdf:rest* ?sl . ?sl rdf:first ?e1 . ?sl rdf:rest ?sln . ?sln rdf:first ?e2 . ?e1 skos:notation ?c1_notation . ?e2 skos:notation ?c2_notation . OPTIONAL { ?e1 skos:prefLabel ?c1_label . } OPTIONAL { ?e2 skos:prefLabel ?c2_label . } }}
c1_notation | c1_label | c2_notation | c2_label |
---|---|---|---|
"001.3" | "Humaniora"@nb | "T1--09" | "Historie, geografisk behandling, biografier"@nb |
"T1--09" | "Historie, geografisk behandling, biografier"@nb | "T2--73" | "USA"@nb |
The script comes with a few extra rules for distinguishing between different types of notes in
WebDewey records and extract entities from these. The entity extraction rules (marked with [*] below)
utilizes a non-standard namespace and are not enabled by default. Specify the --webdewey
flag to
use them.
MARC21XML | RDF |
---|---|
680 having $9 ess=ndf Definition note |
skos:definition |
680 having $9 ess=nvn Variant name note |
wd:variantName [*] for each subfield $t |
680 having $9 ess=nch Class here note |
wd:classHere [*] for each subfield $t |
680 having $9 ess=nin Including note |
wd:including [*] for each subfield $t |
680 having $9 ess=nph Former heading |
wd:formerHeading [*] for each subfield $t |
694 having $9 ess=nml ??? |
SKOS.editorialNote |
7XX having $9 ess=isCaption Relative index term to use as caption |
skos:prefLabel |
Notes that are currently not treated in any special way:
253
having$9 ess=nsx
Do-not-use.253
having$9 ess=nce
Class-elsewhere253
having$9 ess=ncw
Class-elsewhere-manual253
having$9 ess=nse
See.253
having$9 ess=nsw
See-manual.353
having$9 ess=nsa
See-also683
having$9 ess=nbu
Preference note683
having$9 ess=nop
Options note683
having$9 ess=non
Options note684
having$9 ess=nsm
Manual note685
having$9 ess=ndp
Discontinued partial685
having$9 ess=nrp
Relocation689
having$9 ess=nru
Sist brukt i...
Only a small part of the MARC21 Authority data model is converted.
MARC21XML | RDF |
---|---|
001 Control Number |
dcterms:identifier |
005 Date and time of latest transaction |
dcterms:modified |
008[0:6] Date entered on file |
dcterms:created |
065 Other Classification Number |
skos:exactMatch (see below) |
080 Universal Decimal Classification Number |
skos:exactMatch (see below) |
083 Dewey Decimal Classification Number |
skos:exactMatch (see below) |
1XX Headings |
skos:prefLabel |
4XX See From Tracings |
skos:altLabel |
5XX See Also From Tracings |
skos:related , skos:broader or skos:narrower (see below) |
667 Nonpublic General Note |
skos:editorialNote |
670 Source Data Found |
skos:note |
677 Definition |
skos:definition |
678 Biographical or Historical Data |
skos:note |
680 Public General Note |
skos:note |
681 Subject Example Tracing Note |
skos:example |
682 Deleted Heading Information |
skos:changeNote |
688 Application History Note |
skos:historyNote |
7XX Heading Linking Entries |
skos:xxxMatch (see below) |
Notes:
- Mappings are generated for 065, 080 and 083 only if an URI pattern for the classification scheme has been defined in the config.
- SKOS relations are generated from 5XX fields if the fields contain a
$0
subfield containing either a control number or an URI for the related record. The relationship type isskos:broader
if$w=g
,skos:narrower
if$w=h
, andskos:related
otherwise. If$w=r
and$4
contains an URI, that URI is used as the relationship type. Note that$4
must precede$0
(since both subfields can be repeated). - Mappings/relationships are generated for 7XX headings if the fields contain a
$0
subfield containing either the control number or the URI of the related record. If$0
contains a control number, an URI pattern for the vocabulary (found in indicator 2 or$2
) must be defined in mc2skos.record.CONFIG. If$4
contains an URI, that URI is used as the relationship type. Otherwise, if$4
contains one of the ISO 25964 relations, the corresponding SKOS relation is used. Otherwise, the default valueskos:closeMatch
is used. Note that$4
must precede$0
(since both subfields can be repeated).